Electricity suppliers may charge a fee to their customers both for energy consumption, measured in kilowatt-hour (kWh), and for their peak demand, or maximum power rating, measured in kilowatt (kW), that may be assessed during a particular billing period. By and large, peak demand may be assessed and billed monthly, that is, a charge may be assessed based on the maximum demand by the customer for that particular month. Alternative billing schemes, for example, annual peak demand, may also be used in determining these assessments.